The primary stress would normally be on the third syllable where I come from.

I think, like many borrowed words, it has lost its "proper" spelling and pronounciation. I never see it spelled with accents here, and we all say REH-zoo-may. (The first syllable's e sound is like in chest.) (And we are supposed to be a bilingual country, but the practical upshot of that is that all the anglos, myself included, have developed our own way of pronouncing French words which is neither French nor English!)